Flotation of phosphate minerals



Patented May 29, 1945 2,371,129 rLo'rA'noN F rnosrmra MINERALS Ludwig J. Christmann, Yonkers, N. Y.,and

Stephen E. Erickso Calumet, Mlnn., as-

signorsto American Cyanamld Company, New York, N. Y., a corporation of Maine No Drawing. Original application June 20, 1940,

Serial No. 341,438.

tion June 5, 1943, Se

Claims. The present invention relates to the froth flota- Divided and this applicariai No. 489,814

tion of phosphate minerals and more specifically relates to a method of improving the promoting power of the promoters ordinarily employed in concentrating phosphate ore values by froth flotation. This application is a division of our copending application Serial No. 341,438 filed June 20, 1940. I

It is well known in the art that the values of phosphate ores can be concentrated or recovered by froth flotation processes in which fatty acid substances are employed as promoters. Among the more important promoters used heretofore are the free fatty acids themselves such as oleic acid,

fish oil fatty acids, talloel, fatty acid soaps, and

the like. In carrying out the actual froth flotation operation these various promoters may be mixed with an alkali such as caustic soda along witha water-immiscibleoil such as melon and may or may not also contain a frother such as .pine oil or kerosene. While such phosphate recovery processes Have been employed successfully on a commercial basis they are not entirely satisfactory in that it is diflicult to obtain a phosphate concentrate having a low percentage of insoluble material. The value of the phosphate concentrate is very largely determined by the amount of insoluble material which is present and it is therefore very desirable that a phosphate concentrating process be developed which would result in the production of a lower insoluble containing concentrate.

o In accordance with the present invention it has been discovered that the promoting power of the fatty acid type promoters employed in concentrating phosphate materials by froth flotation can very greatly be increased by adding a low percentage of an aliphatic alcohol or aliphatic ether alcohol to the promoter prior to the froth flotation operation. Some of the prior processes have used alcoholic solutions of flotation reagents, e. g., where the alcohol used is equal to or greater than the amount of flotation reagent. In such processes the alcohol was used as a solvent for the flotation reagents and was'merely a method of obtaining the flotation reagents in highly concentrated form. In'the present invention, however, the fatty acid. type flotation reagent is diluted withabout' or less of an alcohol to increase the promoting power, The quantityof alcohol,

employed in carrying out the present invention is very much less than the quantities employed as solvents in the prior solution methods. The exact reason why the promoting power of the phosphate flotation promoters is increased by the diluting with a small amount of an alcohol has not been definitely determined and we do not desire therefore to limit the present invention to any theory or explanation as to why the promoting power is increased.

In connection with the recovery of values from phosphate ores on a commercial scale we have found that we can reduce the percentage of insolubles in the concentrate on an average of about one to two percent when compared to the ordinary fatty acid flotation process, while at the same time the reagent cost is increased only about one cent per ton of phosphate concentrate. and hence, the present invention results in a very economical saving in the concentration of phosphate ores.

;The higher grade concentrate will also bring a better price as a 1% increase in grade is equivalent to about fifteen cents increase in value per ton of concentrate.

In carrying out the present invention the fatty acid promoter is diluted with about 20 orless ofan aliphatic alcohol or aliphatic ether alcohol. This mixture is then employed in the usual manner for conducting the froth flotation. We may, however, mix the fatty acid alcohol mixture with an equal quantity of fuel oil and then add this 50/50 mixture to the'fiotation feed or pulp containing the correct quantity of caustic and then condition for a short time prior to the froth flotation.

It is an advantage of the present invention that the promoting power of the fatty acid type promoters are increased by diluting with 20% or less of any of the well known aliphatic alcohols or ether alcohols and is not limited to any particular alcohol or ether alcohol, Among the allphatic alcohols that have been found to be useful are those such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, octyl; the polyhydroxy alcohols such as glycol, diethylene glycol, or polyethylene glycols, and the various ether alcohols such as mono-methyl ether of diethylene glycol, monoethyl ether of diethylene glycol, mono-butyl ether of diethylene glycol and the like. The term aliphatic alcoho as used in the appended claims is intended to include the unsubstituted monoand poly-hydric aliphatic alcohols and the aliphatic ether alcohols such as those listed above.

The invention will be further illustrated in connection with the following specific examples.

Exsurns l Tests on phosphate ore The oresample used in these flotation tests is from the Brewster, Florida, region, and is a representation deslimed flotation feed.

In running the flotation tests, a charge of the phosphate rock, containing 600 grams of dry solids was employed for each test. Suflicient water was added to give a pulp density of 72% solids. The resultant pulp was agitated by means of a mechanical-type mixer. Reagents were added in quantities as shown in the descriptions for the individual tests (Table 1) and the pulp was then 411101005101 four minutes. Each of the rev-C nt mixtures tested was made up as a 50% solution in light fuel oil before adding it to the flotation Pu p.

contained 9.4% isopropyl alcohol and 90.6%

talloel.

Tests were run on two different day shifts. The results of these tests are given below:

banks of flotation machines. In running the tests the east section 'of'machines was fed talloel and the west section was fed talloel-alcohol mixture.

Attersaitation the pulp was transferred to a I first day laboratory-size Mrsren flotation machine and diluted to 22% solids with water. Air was then admitted to the cell and arougher concentrate r000 00110 11111100 was skimmed 0! for a period or one and a hall section Promote,

minutes. Thisproductwasreplaced intheflota- 501 00 1 Tens/hour 201 00 1 P 1 11. 1 tionmachine, without additional reagents, anda cleaner conoentrate removed by flotation for 0.

1011110.... 30.11 53.03 72.21 7.20 Talloei. 983N101 Ongmimlte- West..- 30.00 54.51 7 73.05 4.75 T511001-01501101 Themetaliureicalresults obtainedinthesetests 1111mmare tabulated in'lable 1. Y

- Team I v Metallurgical data -5 Cleaner concentrate Cleaner telling Rougher tailing Mixture tested 2 04 0 :0 A 5 .3" E 1:; E E .5 3 3 3 2 .1.-1gs..:g5 E a a m E 00 s 1 0: D o a u .3 FM u in a 1 -1 Promoter fluent 3 z g g t g q o '33- 5'' 3 3 k 1a.a$l 03na0- n&5in 1 8191. 28.98 7 41 4- 7 0540 5.22 53.40 0.40 05.02 1:102 20.04 T105011 None 1.00 82.96 28.84 76.32 3.73 00.70 005 50.30 11.00 04.51 10.00 21.20 0 1 0 0. 3323 37.00 74.50 550 0440 2.07 30.31 3.42 50.43 0.01 12.10 Talloel 11-01 Ethyla1cohol0% 1.05 3370 30.07 74.75 510 00.01 4.47 50.05 7.70 50.40 0.02 12.21 Talloel 11-01 Ethyl 01001101 0.70 3300 34.00 75.00 3.00 70.55 3.00 50.03 0.11 01.05 7.70 14.34 T011001 H-9l Isopropyl 11100110 -0%.. 1.00 32.70 32.34 76.43 3.92 74.60 3.92 49.83 5.97 63.74 0.97 19.43 Talloel H-91 Isopropyl a1coh01D% 0.75 30.34 33.00 75.20 512 75.07 4.07 40.22 7.10 01.37 0.15 10.34 Talloe] 11-01 Methyl alcohol-9% 0.00 32.03 20.0 70.30 3.70 00.70 4.57 53.05 7.33 05.02 11.30 22.01 Talloel 21-01%. Methyl 01001101-0 71 0. 75 3302 25.50 70.53 3.32 00.05 5.10 54.24 0.40 00.34 12.00 25.47 1 .0.2.5 None 3270 2200 70.05 3.05 53.73 4.00 50.22 7.11 73.11 17.50 30.10 0.0.1 .4 110 0.75 32.02 32.35 70.01 3.27 75.20 530 53.31 0.00 02.20 0.45 10.04 FO.F.A.01$ Ethylaloo g, 1.00 32.74 20.43 70.20 3.30 00.00 4.14 55.17 0.00 00.30 12.00 24.33 F 0.17. A.--9l E111 1111001101 0 0 0.70 82-71 22.30 75.74 3.40 51.77 7.22 02.05 13.00 70.42 15.05 34.34 TalloelL N050 0.71 32.07 m 70.10 3.70 00.12 500 50.10 0.04 05.52 11.00 23.24 TalloelL-9l Ethylalcohol9% 0.75 32.35 27.42 75.05 3.37 04.20 5.50 57.07 10.01 00.00 12.41 25.70 Talloel L-91 Isopropylalcohol9% 0.75 33.24 33.02 73.73 4.42 73.22 5.00 53.31 0.13 01.20 0.57 17.04 TalloeiL None 1.14 32.03 32.51 70.02 3.05 75.13 4.24 50.02 7.22 03.25 0.15 17.00 T011001L-01 Ethyl 01001101-0% 0.00 32.03 32.31 75.20 3.07 73.05 4.37 50.00 0.74 03.32 10.00 10.31 T011001 L-01 1301115 1 1 aleohol9% 0.00

32.70 30.15 75.77 3.00 00.07 5.00 53.45 0.72 03.00 10.50 20.01 T000010 74 22.00 3001 75.00 4.50 70.40 4.41 40.05 0.50 00.00 7.03 14.04 TalloelO 0. 33.11 31.30 77.18 3.02 73.00 4.45 53.05 7.21 04.10 10.10 10.70 TalloelL-Ql 33.00 37. 70 75.00 5.10 04.00 4.50 30.00 5.37 57.05 5.04 0.04 TalloelL-9l 0.00

The reagents kept constant in the above tests were:

. Lbs/ton Causticsoda. 0.76 Fueloil (total). 4.00

F. 0. F. A. designates ilsh oil fatty acid. Tslloel H, L 62 C designates talloel acid from three diiierent sources.

" Exnrru 2 Second dail Lame scale tests on phosphate rock Feed Concentrate The following comparative tests were run with 00001011 Promoter talloel and talloel-alcohol mixture in the Old Tons/hour 3,? ggy Colony plant of the American Cyanamid Com- 05 pany at Brewster, Florida.

' East- 39. 64 48. 02 73. 77 5. Talloel. In the Old Colony plant the coarse flotation West 41.10 50.30 74.04 4.45 1 51100101001101 1000 is split and treated 111 two separate, 1001101001 0 A third test was run on another day under slightly different conditions. The results are given In these tests the talloel-alcohol mixture used in Table III.

. TABLI III Feed Concentrate Lbs/ton conc. Section 'g Ratio Recov.

B. P. 1... T./hr. B. P. 111101. '1./l1r. 10101011 Talloel NaOH 0.1001101 East 40.30 47.45 73.05 5.00 22.02 0.10 2.07 00.1 14.30 2.32 0.00 West. 40.05 40.31 74.40 5.35 23.21 0.20 2.00 00.3 15.40 1.00 0.0 0.21

0 place 0! W60 mixture 01 tailoel and fuel oil.

In) Z Y ns isofiropyl alcohol and 20 gallons fuel oil added to 255 gallons /50 mixture talloel and iuel oil. This mixture used on west section in 2. In therecovery of values from phosphate rock by froth flotation, the process which comprises carrying the flotation out in the presence of a fish oil fatty acid diluted with about 10% of.

4. In the recovery of values from phosphate.

rock by froth flotation, the process. which comprises subjecting an aqueous pulp of phosphate rock to froth flotation in the presence of a flsh oil fatty acid diluted with from about 9% to not more than about 20% of an aliphatic alcohol.

5. In the recovery of values from phosphate rock by froth flotation, the process which comprises subjecting an aqueous pulp of phosphate rock to froth flotation in the presence of talloel diluted with from about 9% to not more than about 20% of an aliphatic alcohol.

6. In the recovery of values from phosphate rock by froth flotation, the process which comprises subjecting an aqueous pulp of phosphate rock to froth flotation in the presence of talloel diluted with about 10% of an aliphatic alcohol.

7. In the recovery of values from phosphate rock by froth flotation, the process which comprises subjecting an aqueous pulp of phosphate rock to froth flotation in the presence of talloeldiluted with about 10% of ethyl alcohol.

8. In the recovery of values from phosphate rock by froth flotation, the process which comprises subjecting an aqueous pulp of phosphate rock to froth flotation in the presence of oleic acid diluted with from about 9% to not more than about 20% of an aliphatic alcohol.

9. In the recovery of values from phosphate rock by froth flotation, the process which comprises subjecting an aqueous pulp of phosphate rockto froth flotation in the presence of oleic acid diluted with about 10% of an aliphatic alcohol.

10. In the recovery of values from phosphate rock by froth flotation, the process which comprises subjecting an aqueous pulp of phosphate rock to froth flotation in the presence of oleic acid diluted with about 10% of ethyl alcohol.

LUDWIG J. CI-IRIS'IMANN. S'IEPHEN E. ERICKSON. 

